Let algae do the dirty work.
Researchers at Rochester Institute of Technology are developing biodiesel from microalgae grown in wastewater. The project is doubly “green” because algae consume nitrates and phosphates and reduce bacteria and toxins in the water. The end result: clean wastewater and stock for a promising biofuel.
The purified wastewater can be channeled back into receiving bodies of water at treatment plants, while the biodiesel can fuel buses, construction vehicles and farm equipment. Algae could replace diesel’s telltale black puffs of exhaust with cleaner emissions low in the sulfur and particulates that accompany fossil fuels.
Algae have a lot of advantages. They are cheaper and faster to grow than corn, which requires nutrient-rich soil, fertilizer and insecticide. Factor in the fuel used to harvest and transport corn and ethanol starts to look complicated.
In contrast, algae are much simpler organisms. They use photosynthesis to convert sunlight into energy. They need only water — ponds or tanks to grow in — sunlight and carbon dioxide.
“Algae — as a renewable feedstock — grow a lot quicker than crops of corn or soybeans,” says Eric Lannan, who is working on his master’s degree in mechanical engineering at RIT. “We can start a new batch of algae about every seven days. It’s a more continuous source that could offset 50 percent of our total gas use for equipment that uses diesel.”
Cold weather is an issue for biodiesel fuels.